1. Field of the Invention
The present invention relates to a lens barrel having an auto-focusing apparatus and a manual focusing apparatus.
2. Related Background Art
Conventionally, in order to switch between an auto-focusing apparatus and a manual focusing apparatus, a photographer manually rotates or slides an external switching member to mechanically switch an internal switching mechanism.
However, when a photographer wants to select a manual focusing photographing mode so as to perform a photographing operation of an object which cannot be automatically focused or to perform an out-of-focus photographing operation according to a given photographing will, he or she must manually rotate or slide the external switching member, and it is difficult to perform a quick switching operation.
In a so-called "go home" photographing function, an arbitrary photographing distance is stored in advance in a lens, and the lens is driven to the arbitrary photographing distance after a photographing operation with another photographing distance. This function cannot be realized by a conventional method since a photographer must manually rotate or slide the switching member to mechanically drive the internal switching mechanism in the manual focusing mode although this function may be realized in the auto-focusing mode.
In place of the conventional method of mechanically driving the internal switching mechanism, an operation method of electrically driving the internal switching mechanism has been proposed. However, a method using a bistable type solenoid suffers from a large power consumption, and a battery is considerably consumed. Therefore, there is no easy, economic switching apparatus which can satisfy needs of a photographer.